Don't just 'put' him out - stay out with him or take him out on a lead. Go right back to puppy basics and get up early to make sure he has a chance to be clean, as Ratter says every time he eats or drinks and also when he has been playing or sleeping take him out. How often do you take him out for exercise? When its raining or snowing put a coat on and take him out (that is, put a coat on him as well as you). Just because he's only a Chi doesn't mean he doesn't need to be exercised whatever the weather.